Optical fibre coupler and a fabrication method for the same

摘要

In order to provide an optical fiber coupler in which the mode coupling state between the constituent optical fibers (12) is a multiple mode coupling stage, the optical fiber coupler is formed by fusing together adjacent lateral portions of at least two constituent optical fibers (12) which extend alongside one another and then elongating the fused section to form a fused-elongated region (13), an "SZ" twist perturbation being introduced to the fused elongated region (13). <IMAGE>